The aim of this project is to develop a practical model of myeloid cell mediated immune surveillance to investigate the trafficking signals used by these cells at rest and during disease states (i.e. infection, allergic, and inflammatory reactions). Also part of this project is a related initiative to study the role of phagocyte oxidants in the development of chronic inflammatory disease states. Projects: 1. In vitro proliferation and differentiation of hematopoietic progenitors into macrophages/dendritic cells. 2. Characterization of the functional maturation of dendritic cells, comparing homeostasis to disease states. 3. In vivo trafficking of fluorescent labeled dendritic cells. 4. Examine bacterial and viral antigen, and CpG motiff mediated dendritic maturation. 5. Using gene expression analysis we will investigate the basic differences between the precursor, immature and mature dendritic cells. 6. Dendritic cell mediated tolerance.